Review of Autonomous Undersea Vehicle (AUV) Developments 
Table 11. Ocean Explorer Payload Interface Specifications = 
Available Power: 
48 Volts (42-56V) 
5A max. current 
Cables/Connectors: 
Power/LonTalk Network 
SeaCon FAWM Series 
Pin 1 BATTERY GND 
Pin 2 BATTERY +48V 
Pin 3 BATTERY GND 
Pin 4 BATTERY +48V 
Pin 5 BATTERY GND 
Pin 6 BATTERY +48V 
Pin 7 LonTalk Data A 
Pin 8 LonTalk Data B 
Note: LonTalk Data Lines A&B must be a twisted pair. 
Ethernet/Serial 
SeaCon FAWM Series 
Pin 1 TD+ 10Base-T Ethernet 
Pin 2 TD- 10Base-T Ethernet 
Pin 3 RD+ 10Base-T Ethernet 
Pin 4 RD- 10Base-T Ethernet 
Pin 5 EIA-232 Common 
Pin 6 ElA-232 TX 
Pin 7 EIA-232 Common 
Pin 8 EIA-232 RX 
Note: 10Base-T TD+/- and RD+/- are twisted pair. 
Power 
The Power/LonTalk network cable supplies 48-volt power. The maximum allowable current for a 
payload is 5A. The Ocean Explorer AUV total battery storage capacity is 40 Ampere-hours at a 
nominal voltage of 52V. This capacity is divided into eight 5-Ampere-hour battery packs. If the 
total capacity is insufficient, additional battery modules can be added to the payload compartment. 
BATTERY GND (pins 1, 3, and 5) should not be connected to the pressure vessel (i.e., seawater) 
which houses the payload electronics. If the payload circuit ground must be connected to 
seawater, then an isolated power supply should be used. 
Communications 
The preferred method of communication between the AUV and payload is through the LonTalk 
network (connections in the Power/LonTalk cable). The Lon/Talk network is used to communicate 
directly with any of the sensors or actuators that comprise the AUV's distributed control network. 
Typically a serial gateway module is provided to the payload manufacturer for incorporation into the 
payload. The serial gateway module provides a bridge between EIA-232 communications and the 
LonTalk network. Custom software for the serial gateway module must be written to implement the 
desired functionality. 
The Ethernet/Serial cable contains a 3-wire ElA-232 serial communication channel that connects to 
a serial gateway module in the main pressure vessel. This module provides an EIA-232 to LonTalk 
network interface. Custom software for the serial gateway module must be written to implement 
the desired functionality. This connection would normally be used when installation of a serial 
gateway module in the payload is impractical. 
The Ethernet/Serial cable also contains a 4-wire (two twisted pair) 10Base-T Ethernet channel. 
This is connected to a 10Base-T hub in the main pressure vessel. Either a cable or wireless 
Ethernet links the AUV to a surface vessel. 
58 
